This invention relates to fuzzy computers.
The digital computer was created by harmonizing the concept of a stored program, Boolean algebra and the stable operation of binary hardware, and the comprehensive development of logic and thorough processing of data have been made possible by the continuous operation of such a computer. The stable operation of the digital computer assures high reliability, and digital computer systems are continuing to grow in scale. A digital computer is capable of being programmed at will as long as the program does not contain information on the same mental level as that of human beings. In this sense, a digital computer is even referred to as a general-purpose machine. The realization of digital computer systems is greatly revolutionizing human life and human society.
The very important concept of "fuzziness" has come about by considering what and how human beings think and how they communicate with one another. L. A. Zadeh proposed the concept of fuzzy sets in 1965. Since then, theoretical studies concerning fuzziness have found their way into print in a large number of technical papers, but reports on applications are still few and these have merely relied upon the assistance of binary digital computers.
Research on fuzziness emphasizes that human knowledge is based on accummulated experience that is to be generalized in the form of linguistic information, as is the know-how possessed by specialists. This linguistic information generally possesses vagueness, obscurity, uncertainty, incompleteness or impreciseness and is characterized by a membership function. The grade of membership is expressed by numerical values in the region of from 0.0 to 1.0 and varies within this range.
When linguistic information is handled by a digital computer, the grades (values) of membership are represented by binary codes. The binary-coded values are stored, transferred and operated on again and again in binary electronic circuits in accordance with a stored program. As a result, a long period of time is required to process fuzzy information by a digital system. Furthermore, the binary-coded values require an unbelievably large number of elements in order to be stored and operated upon. Though a digital computer is indeed a general-purpose machine as mentioned above, it is not necessarily best suited to the real-time processing of fuzzy information. Thus, there is need of another type of machine capable of processing fuzzy information effectively and at high speed.